How to detect Windows Application Dark mode

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How to detect Windows Application Dark mode

Deshmukh, Gaurav 30

What is the way to detect windows application dark mode setting (If it is dark or light), in a C# WPF application.

Settings > Personalization > Colors > “Choose your default app mode”

User's image

Screenshot from Windows 10 operating system.

I am aware of most of the ways (to detect this setting) that can be found on forums, like below. But was not able to find any official documentation for the same.

Using Registry value: Path: Computer\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Themes\Personalize Key: AppsUseLightTheme This is most of the time reliable, but the value is only available after the user has changed the setting at least once.
Using Windows UI ViewManagement This involves identifying the foreground, background color and based on that consider if it is Dark or Light theme. But this does not seem the right way (for long term).
Using uxtheme.dll ‘s ShouldAppsUseDarkMode function. This did not work for me as expected (or was not able to provide the correct value most of the time).

So, require a Microsoft Windows documented, official & reliable way by means of which it is possible to detect the “Choose your default app mode” setting programmatically (WPF, C#).

Also are their similar ways to detect this in different versions of Windows (8.1, 10, 11, etc.)

Xiaopo Yang - MSFT 12,736 Reputation points Microsoft External Staff

2023-01-18T07:23:57.0466667+00:00

but the value is only available after the user has changed the setting at least once.

Without change, the default app mode is Light.

But this does not seem the right way (for long term).

As Castorix31 answered, this is a document way but UISettings Class is supported by Windows 10 (introduced in 10.0.10240.0) and later.

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Xiaopo Yang - MSFT 12,736 Reputation points Microsoft External Staff

2023-01-18T07:23:57.0466667+00:00

but the value is only available after the user has changed the setting at least once.

Without change, the default app mode is Light.

But this does not seem the right way (for long term).

As Castorix31 answered, this is a document way but UISettings Class is supported by Windows 10 (introduced in 10.0.10240.0) and later.

Answer 1

Castorix31 91,501

There is this MSDN doc : Know when Dark mode is enabled about the second method

(but I generally use the first method by reading the registry...)

Deshmukh, Gaurav 30 Reputation points

2023-01-24T13:47:15.0933333+00:00

Thanks for your prompt response.

After much investigation it looks like this is the only documented way (as of now). Will have to go forward with this.

Using Windows.UI.ViewManagement, UISettings's GetColorValue method and the suggested calculation.

(Not preferring Registry method as it becomes unreliable in some scenarios)
Castorix31 91,501 Reputation points

2023-01-24T14:22:35.9966667+00:00

Not preferring Registry method as it becomes unreliable in some scenarios

Do you mean in the case you described above :

"but the value is only available after the user has changed the setting at least once."

(it always worked for me as I only tested it on my PC (Windows 10))
Deshmukh, Gaurav 30 Reputation points

2023-01-25T05:04:29.7633333+00:00

Yes, As I investigated the registry value is not present for user unless the user has made change to this setting (at least once). In case the user has never accessed the settings.

Once created it remains there and gets updated as the settings are changed. (Have not seen the registry value getting removed).

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How to detect Windows Application Dark mode

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